Matt Cutts Updates Google's nofollow Use
This is probably the last update I will post about this issue since I have covered the topic in two previous posts, What is With the rel=nofollow Penalty and Update: What is With the rel=nofollow, but it is worth an additional follow up here with Matt Cutts latest post, Quick comment on nofollow. Matt has updated Google's interpretation of the use of nofollow and answered some questions that had been flying around lately. I did learn some new information about the issue from reading the lastest posts, and when you should consider using the rel=nofollow code with your links. Matt also answered some of the questions posed by seomoz.org in his post, Matt Cutts on Nofollow, Links-Per-Page and the Value of Directories, where he asked several unanswered questions about the nofollow issue. Most of his remarks come from a post to the Google Group, Google Webmaster, where he says that webmasters are free to use the nofollow how they see fit of course but something else I had been wondering and just didn't ask yet, was if I have my robots.txt file modified where the entire directory is disallowed, will that work too? Apparently so.
Matt states in the Google group post, Appropriate uses of nofollow tag -- popular pick , where he says just that. Thanks for answering my question without me asking.
The nofollow attribute is just a mechanism that gives webmasters the ability to modify PageRank flow at link-level granularity. Plenty of other mechanisms would also work (e.g. a link through a page that is robot.txt'ed out), but nofollow on individual links is simpler for some folks to use. There's no stigma to using nofollow, even on your own internal links; for Google, nofollow'ed links are dropped out of our link graph; we don't even use such links for discovery. By the way, the nofollow meta tag does that same thing, but at a page level.
Some of the information I took from all these posts is that the nofollow issue and its use is far more broad than just for the paid links you might have on your site, and it is used to keep spam off your site, or at least from being indexed through your site, lowering the possible usefulness and ranking of your site. To be moderately educated on this issue will certainly not hurt your abilities as a webmaster or to help market other clients sites and ecommerce stores. Things to remember for me would be:
You can use your robots.txt file instead
Using your robots.txt file will generate the same good results, and might be easier than worrying about each individual link.
You can use a meta tag
Placing a nofollow meta tag at the top of your page will keep the index from taking place on a page level
Use it on pages that won't convert well
Using a nofollow tag on a sign-in link or an account link is a good idea too. These links will not produce any positive effect on your traffic or ranking, it doesn't have to just be a paid link, any link that doesn't become an asset to your site.
Most of the focus on the nofollow topic has been geared towards blogs with comments being posted but I will write an article coming up that shows how using this in combination with your ecommerce stores can be a good thing as well, it is not just for the bloggers. Any advantage you can gain over your competition on your ecommerce platform is good, and I would expect few of the very small ecommerce companies recognizes this as an issue.